It is easy enough with a macro. The following assumes the result will go in the last cell in the column containing the cursor and that there are no merged/split cells in the table.
Code:
Sub CountNums()
Dim oTable As Table
Dim lngCount As Long: lngCount = 0
Dim oCell As Cell
Dim oRng As Range
Dim i As Integer
Dim iCol As Integer
Dim iRow As Integer
Set oTable = Selection.Tables(1)
iRow = oTable.Rows.Count
If Selection.InRange(oTable.Range) = True Then
iCol = Selection.Cells(1).ColumnIndex
For i = 1 To iRow - 1
lngCount = lngCount + Split(oTable.Columns(iCol).Cells(i).Range.Text, Chr(32))(0)
Next i
Set oRng = oTable.Columns(iCol).Cells(iRow).Range
oRng.End = oRng.End - 1
oRng.Text = lngCount
End If
lbl_Exit:
Set oCell = Nothing
Set oRng = Nothing
Exit Sub
End Sub